System of transmitting signals electrically through conductors.



F. FISHER. SYSTEM OF TRANSMITTING SIGNALS ELEGTRIGALLY THROUGH GONDUCTORS.

APPLICATION FILED FEIL3, 1910.

u m r m .3 m. 2 n A y e m fi. d m

m 1% a n lv P M W onriuzn sTA-rns PATENT ()FFICE.

FRANK rrsrrnraor NEW YORK, N. Y.

SYSTEM- OF TRANSMITTING SIGNALS ELECTRIGALLY THROUGH CONDUOTORS.

' To all whom it may concern:

Be it known that I,-FRANK Flsnnn, a subect of the King of the United Kingdom of Great Britain and Ireland, and a resident ofthe borough of'Brooklyn, in the city of New York, county of Kings, and State of New York, have invented certain new and useful Improvements in Systems of Transmitting Signals Electrically Through Conductors, of which the followingis a specification, reference being had therein to the accompanying drawings, which form'a partthereof.

My invention. relates to systems of transmittmg signals electrically through conductors and more particularly to means for relievin ;the receiving coil from inductive distur ances.

' The main object of the invention is to provide a system a of transmitting signals electrically through conductors, wherein the receiving instrument will not be afi'ected by inductivedisturbances in the'line due to a variance in the earths potential.

A further object is 'to provide in such a system, means whereby all inductive disturbances will be neutralized, or absorbed, be-

fore reaching the receiver thus creating a neutral zone about the receiver, and permitting only the sendin current to affect it thereby insuring relia ility inthe action of said receiver.

A still further object is to provide a system of this kind, which will be especially adapted for use in multiplex telegraphy, either inaerial linesor in submarine cables, and which will prote'dt the receiver from inductive disturbances whether such arise from atmospheric eon litions, the presence of charged, electrical cor ductors in close juxta position to the line, tr self-induction at any point of the system.

' A still further object is to provide a system of this charabt er wherein the. returncurrent may be through the earth, thus avoiding the necessity for a complete metallic circuit, with special windings or other expedients to eliminate or neutralize such disturbances. 1 v

A still further object is: to provide a system capable of use witha multi )lex tcle- A graph system employing a bridge similar to the lvheatstone ridge, wherein the resistance on opposite sides of the receiver may Specification of Letters Patent. Application filed February 3, 1810. Serial $0. 541,922.

Patented May 23. 1911.

I be permanently balanced, so as to avoid the necessity for' frequent readjustment to balance the resistances in the main line and in the artificial cable, to ermit the duplex or multiplex working' of t e main line.

. A still further object is to provide a system wherein the residuary current in the receiving coil, dueto self-inductiomwill' be rapidly discharged to avoid the retardation of the sending current by reason of such residuary current in the said coil, thus not only'increasing the capacity of the receiving coil for rapid work, whether manual or automatic, through the elimination of this re siduary current, but also permitting the use of light tensioned springs upon *a receiving armature which will aid in accomplishing the same result.

A still further object is to rovide a system of this character wherein the ground connection of the receiving instrument may be made adjacent thereto, and any inductive disturbances due to the variance in the potential of the earth adjacent to this ground connection would be so neutralized about the receiver itself, as to prevent the energizing or decnergizing of the said receiver by such disturbances.

The invention consists primarily in a sys tem of transmitting signals electrically through conductors, embodying therein a sending instrument, and a receiving instrument connected therewith, said receiving instrument being arranged in a zone insensible to inductive disturbances in the system; and in such other novel arrangements of parts as are hereinafter set forth and described and more particularly set forth in the claims hereto appended.

The accompanying drawing is a diagrameach end is similar to that at the other, this.

device being especially applicable to multiplex Work.

In the accompanying drawings, I have shown atB the batteries at opposite terminals of the line L, and at K the sending.

keys by means of which the current is impressed upon the line. The keys shown in the drawings are the ordinary reversing keys used in submarine cable work and the wiring shown in connection therewith is the ordinary wiring with such a key. This type. of key and wiring is non-essential to the invention and is shown merely for illustrating the application of'the invention to submarine cable work wherein it will have especial applicability. One contact of the key K is in electrical connection with the line L and with the earth connection AG, by the branch wires a a extending on opposite sides of the receiver R. The line AC is connected to earth at E and contains therein a resistance C preferably in the form of a variable rheostat whereby the resistance of the earth connection AC may be brought to exactly balance with the resistance of the line' L. The line AC, and its contained resistance, corresponds with the ordinary artiother multiplex telegraphicsy'stem' and no claim of invention is made thereto. 'With the present practice, however, it is necessary to preserve a condition of equal resistance in the-main line and in the artificial cable or I ground line, by frequent balancing of these two lines owing to the inductive disturbances in one line or the other resulting from the change of potential'in the earth or in the air.

A loss of this balance not only interferes with the sending current, causing it to energize the receiving coil, but the inductive disturbances resulting therefrom (which are always present in the system to a greater or less extent) have the same effect upon the receiving coil and thus interfere with the receiving of messages as well as the sending thereof. When a delicate receiving instrument such as a siphon receiver is used, such disturbances during a storm frequently necessitate-the abandonment of duplex working or of even simpler: workin when conditions are very bad. It is to obvlate this difficulty, that I have produced my present system which is based upon the creation of a zone insensible to inductive disturbancesthroughout the system about the receiving instrument,'thus isolating this system to all impulses excepting those of the receiving curren This arrangement heretofore deoint at which ground is had for the line A is the ordinary wiring of a submarine cable or In carrying out my invention, I have proce'eded upon the premise that, the potential of the earth at any point is uniform and that by locating shunt circuits on opposite sides of the receiver, running to ground, the conditions upon both sides'of. said receiver j will always be uniform, and thus preclude. thev passage of induced currents through said system whether from ground, or from the line L.. These shunt circuits include .75 therein suitable instrumentsadapted' to ab: sorb or dissipate induced currents, or discharge them to ground. Preferably the in-. struments referred to consist of the resist-" P ance s or 8 connected in series with the con- 8 denser 0' or 0', the ground connection being at E E respectively, the ground of these shunt circuits being taken at substantially the-same point as the ground E. I connect the resistances and the condensers in series, with the former nearer the receiver toi increase the tension of the current passing to the latter. By this arrangement it will be observed that when a balance is once se-' cured in the system between the line L v and the ground connection AC, the receiver is not aflected by the sending current; and that the. receiving current, (assuming the impulse to 1 be a positive impulse) will pass from L to R- through r, from R to 1-, and through the resistance C to ground through the line AC, j the shunt circuits I I, through the condensers a a forming a perfect insulation so far as the voltaic current is concerned. If the system employed uses an induced current instead of-a direct voltaic current, this may be compensated for by regulating the capacity of the condensers 0 0 so that the pulsating receiving current will not charge same, thus eliminating all pulsating currents of Y a frequency not corresponding with that of the receiving current. If there beja variance in the earths potential at either station, any inductionin the line AC will, be neutralized at the point of joinder' of similar polarity at'this point and a similar polarity will be maintained onoppo'site sides of the receiver by reason of the arrangement, location and manner of coupling of' the shunt circuits I I, thus creating a neu-. tra'l zone within which is the receiver. .It is i also apparent that if such inductive dis-' turbances occur along the line L whether such result from faults in the line, the 'presence of adjacentcharged electrical con ductors or any reason whatsoever, suchpul eating currents will be shnnted'to ground through the line .I', resistance .9 and. condenser 0, thus protecting the receiving in strument from all such pulsating currents,

or elsebe eliminated or absorbed by a current of similar polarity, intensity .and'frequency at thepolnt of connection, of the wine I and r. Thisflelimination of induced c 110 the shunt line I, with theline 7" through the avoiding those losses in time, and those errors resulting from the temporary loss of balance in the system.

.Wheh messages are being transmittedwith great rapidity, whether such messages be sent by hand or automatically, there is sometimes a residuum in the receiving coil, due

,to self-induction which interferes with the proper recording of the messages. I have found that the arrangement of shunt circuits above described also eliminates this difficulty and permits a.more rapid sending of messages than is possible with the ordinary mu'ltiplex system.

.It is not my intention to limit my invention to the details of this system shown in the accompanying drawings, such showing being merely for purposes of illustration. I believe it to be broadly new to provide in a system of this character a receiving instrument arranged in a zone insensible to iiidu'ctive disturbances'in the system, and I intend to claim such broadly. Having described the invention, what 1 claim as new, and desire to have protected by Letters Patent, is

1. A system of the character described embodying therein a sending instrument and I a receiving instrument connected by an electrical conductor, or line, said receiving instrument being connected to ground, and the line on opposite sides of said receiving instrument being connected to ground through shunt circuits to ground containing therein respectively a resistance and a condenser .coupledin series, the resistance being between the condenser and'the receiver.

2. A system of the character described 1 embodying. therein" an electrical conductor,

or line, means for impressing current 1mpulses on said line, receivers, each terminal of said line being connected with said means for impressing currentimpulses on said line and with one of said receivers, the terminals of which receiver are respectively in connection with said line and with local ground, and'shunt circuits on opposite sides of said receiver to localground, containing therein 1 respectively a resistance and a condenser coupled in series, the reslstance being he tween the condenser and the receiver.

33A system of the character described embodying therein a sending instrument and a receiving instrument including therein an electi'o-magnet, an electrical conductor connecting said instruments, said electro-mag net being connected to local earth through a conductor equaling in resistance the resistance of said first named conductor, a

shunt circuit extending from said connection adjacent to said electro-magnet to ground,

said shunt circuit including therein a reslstance and a condenser coupled inseries.

4. A system of the character described embodying therein a line, a sender for imsistance and a condenser coupled in series,

whereby inductive disturbances throughout the system will be shunted to earth on either side of, said receiver.

5. A. system of the character described embodying therein a line, a sender for impressing current impulses on said line, a receiver the terminals of which are respectively in connection with said line and with ground through a resistance equaling the resistance of said line, an electrical connection between said resistance and said sender, andshunt circuits on opposite sides of said receiver to' ground containing therein a variable resistance and a condenser coupled in series, whereby inductive disturbances throughout the system will be shunted to earth on either side of, said receiver.

6. A system of the character described embodying therein a line, a sender for impressing current impulses on said line, a receiver the terminals of which are respectively in connection with said line and with ground through a resistance equalingthe resistance of said line, and electrical connection between said resistance and s id sender, and shuntcircuits on opposite si es of said receiver to ground containing therein a resistance and an adjustable condenser coupled 'in series, whereby inductive disturbances throughout the s stem will be shunted to earth on either sic e of, said receiver.

7. A system of the character described, embodying therein a line, a sender for imoressin currentim )ulses on said line a receiver the terminals of which are respectively in connection with said line and with ground through a resistance equaling the resistance of said line, an electrical connection between said resistance and said sender, and shunt circuits on opposite sides of said receiver to ground containing therein a variable rcsistance and an adjustable condenser coupled in series, whereby inductive, disturbances throughout the system will be shunted to earth on either side of, said receiver.

8. A system of the character described,

embodying therein. a line, a Whcatstone,

bridge, the terminals of which are respec tively connected with said line, and with a condition of similar polarity will be pre- I variable resistance to ground beyond the served on opposite sides of said receiver.

bridge, a sender for impressing. current im- In witness whereof, I have hereunto pulses on said line, a receiver located in the aflixed my signature, this 1st day of Feb- 5 bridge, and shunt circuit; on opposite 1slides ruary, 1910, in the presence of two witnesses. 1::

of said receiver to groun containing t ere- I in a resistance and a condenser coupled FRANK FISHER in series, whereby inductive disturbances Witnesses: throughout the system will be shunted to F. T. WENTWORTH, 9 earth on either side of the receiver and a P. V. WENING. 

